<?xml version="1.0" encoding="UTF-8"?><?xml-stylesheet type="text/xsl" href="static/style.xsl"?><OAI-PMH xmlns="http://www.openarchives.org/OAI/2.0/" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.openarchives.org/OAI/2.0/ http://www.openarchives.org/OAI/2.0/OAI-PMH.xsd"><responseDate>2026-06-07T19:59:42Z</responseDate><request verb="GetRecord" identifier="oai:docta.ucm.es:20.500.14352/100165" metadataPrefix="qdc">https://docta.ucm.es/rest/oai/request</request><GetRecord><record><header><identifier>oai:docta.ucm.es:20.500.14352/100165</identifier><datestamp>2025-03-18T12:50:39Z</datestamp><setSpec>com_20.500.14352_14</setSpec><setSpec>col_20.500.14352_15</setSpec></header><metadata><qdc:qualifieddc xmlns:qdc="http://dspace.org/qualifieddc/" xmlns:dc="http://purl.org/dc/elements/1.1/" xmlns:dcterms="http://purl.org/dc/terms/" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:doc="http://www.lyncode.com/xoai" xsi:schemaLocation="http://purl.org/dc/elements/1.1/ http://dublincore.org/schemas/xmls/qdc/2006/01/06/dc.xsd http://purl.org/dc/terms/ http://dublincore.org/schemas/xmls/qdc/2006/01/06/dcterms.xsd http://dspace.org/qualifieddc/ http://www.ukoln.ac.uk/metadata/dcmi/xmlschema/qualifieddc.xsd">
   <dc:title>How to Build a Functional Connectomic Biomarker for Mild Cognitive Impairment From Source Reconstructed MEG Resting-State Activity: The Combination of ROI Representation and Connectivity Estimator Matters</dc:title>
   <dc:creator>López García, María Eugenia</dc:creator>
   <dc:creator>Bruña Fernández, Ricardo</dc:creator>
   <dc:creator>Cuesta Prieto, Pablo</dc:creator>
   <dc:creator>Marcos Dolado, Alberto</dc:creator>
   <dc:creator>Maestu Unturbe, Fernando</dc:creator>
   <dcterms:abstract>Our work aimed to demonstrate the combination of machine learning and graph theory for the designing of a connectomic biomarker for mild cognitive impairment (MCI) subjects using eyes-closed neuromagnetic recordings. The whole analysis based on source-reconstructed neuromagnetic activity. As ROI representation, we employed the principal component analysis (PCA) and centroid approaches. As representative bi-variate connectivity estimators for the estimation of intra and cross-frequency interactions, we adopted the phase locking value (PLV), the imaginary part (iPLV) and the correlation of the envelope (CorrEnv). Both intra and cross-frequency interactions (CFC) have been estimated with the three connectivity estimators within the seven frequency bands (intra-frequency) and in pairs (CFC), correspondingly. We demonstrated how different versions of functional connectivity graphs single-layer (SL-FCG) and multi-layer (ML-FCG) can give us a different view of the functional interactions across the brain areas. Finally, we applied machine learning techniques with main scope to build a reliable connectomic biomarker by analyzing both SL-FCG and ML-FCG in two different options: as a whole unit using a tensorial extraction algorithm and as single pair-wise coupling estimations. We concluded that edge-weighed feature selection strategy outperformed the tensorial treatment of SL-FCG and ML-FCG. The highest classification performance was obtained with the centroid ROI representation and edge-weighted analysis of the SL-FCG reaching the 98% for the CorrEnv in α1:α2 and 94% for the iPLV in α2. Classification performance based on the multi-layer participation coefficient, a multiplexity index reached 52% for iPLV and 52% for CorrEnv. Selected functional connections that build the multivariate connectomic biomarker in the edge-weighted scenario are located in default-mode, fronto-parietal, and cingulo-opercular network. Our analysis supports the notion of analyzing FCG simultaneously in intra and cross-frequency whole brain interactions with various connectivity estimators in beamformed recordings.</dcterms:abstract>
   <dcterms:dateAccepted>2024-02-08T08:15:19Z</dcterms:dateAccepted>
   <dcterms:available>2024-02-08T08:15:19Z</dcterms:available>
   <dcterms:created>2024-02-08T08:15:19Z</dcterms:created>
   <dcterms:issued>2018-06-01</dcterms:issued>
   <dc:type>journal article</dc:type>
   <dc:identifier>https://hdl.handle.net/20.500.14352/100165</dc:identifier>
   <dc:identifier>1662-4548</dc:identifier>
   <dc:identifier>10.3389/fnins.2018.00306</dc:identifier>
   <dc:identifier>1662-453X</dc:identifier>
   <dc:language>eng</dc:language>
   <dc:relation>MR/K004360/1</dc:relation>
   <dc:relation>FIS2013-41057-P</dc:relation>
   <dc:relation>TEC2016-80063-C3-2-R</dc:relation>
   <dc:relation>PSI-2015-68793-C3-1-R</dc:relation>
   <dc:relation>FPU13/06009</dc:relation>
   <dc:relation>Dimitriadis SI, López ME, Bruña R,Cuesta P, Marcos A, Maestú F andPereda E (2018) How to Build aFunctional Connectomic Biomarker forMild Cognitive Impairment FromSource Reconstructed MEGResting-State Activity: The Combination of ROI Representationand Connectivity Estimator Matters.Front. Neurosci. 12:306 doi:10.3389/fnins.2018.00306</dc:relation>
   <dc:rights>http://creativecommons.org/licenses/by/4.0/</dc:rights>
   <dc:rights>open access</dc:rights>
   <dc:rights>Attribution 4.0 International</dc:rights>
   <dc:publisher>Frontiers</dc:publisher>
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